Walter m



@70645: BY I May 13, 1930. wfMJcRoss 1,758,147

HEATING SYSTEM CONTROL Filed Jan. 5l, 1927 IN VEN TOR.

ciency or under optimum Patented May 13, 1930 UNITED vSTATES PATENTOFFICE WALTER M. CROSS, 0F KANSAS CITY, MISSOURI, ASSIGNOR TO CROSSCOAL-O-MATIC COMPANY, 0F KANSAS CITY, MISSOURI, A CORPORATION 0FMISSOURI p HEATING-SYSTEM CONTROL Applicatin led Januaryv 31, 1927.Serial No. 164,953.

This invention relates to improvements in a heating system control andrefers more particularly to a dual system of control; one phase of theheating system operating the fuel feed and force draft mechanism anddepending upon its actuation by variations in the room temperature ofthe dwelling to be heated; the other control functioning the fuel feedand force draft by predetermined minimum temperatures either inthefurnace or combustion pot o1. the temperature of the water circulatingthrough the boiler or hot water system.

The control is in connection with an automatic stoker and ace set-upwhich is op'- erated either at maximum conditions of elfi'- operating orcombustion conditions on one hand and bank fire conditions of operationon the other. In brief the control is such that as normally operated theheat supplied to the dwelling will be dependent primarily upon thethermostatic control functioned yby the room temperature,

y while the secondary control, either in the combustlon pot or actuatedby the temperature of the boiler `water will serve primarily to keep thefire alive or prevent'extinguishment when the system is not being drawnupon for heat to the dwelling.

This application is a continuation in so far as the control is concernedof my previous apphcations, Serial No. 44,604, filed July 18, and SerialNo. 147,667, filed Nov. 11,

Fig: 1 of the drawing depicts ,a sectional slde view ofthe end feedStoker showing the manner of installing the control in connection with asteam boiler setting.

Fig. 2 shows the electrical control system.

Referring to the a common type of furnace setting, in which arepositioned the flue tubes 2, water being circulated around the flues inthe boiler 3. The combustion space is shown at 4 in the lower part ofwhich is a combustion pot 5, to wh feed hopper 6, through` thelongitudinal passage 7, in which is positioned a screwconveyor 8. Thescrew conveyor is driven from a motor 9 upon whose shaft 10 is mounted adrawings, at 1 is shown ich is fed a coal or coal slack from theA worm11 meshing with'the worm gear 12, which reciprocates a verticalconnecting rod 13 which functions a pawl, not shown in the drawings, butwhich engages the ratchet wheel 14 mounted upon the shaft 8a, which isan elongationof the conveyor screw shaft. The sprocket V wheel and chainmechanism shown at 15 manipulates an automatic dump grate which forms nopart of the present invention. On the shaft 10 is also mounted a blowerfan 16 which drives air through the aperture 17 discharging it throughthe duct 18 into the bed of re contained in the combustion pot throughtuyres 19.

operation the automatic Stoker is functioned in the same manner as anycommon under-feed combustion apparatus, the coal being transferred fromthe hopper by means of the conveyor screw through the passage 17 andinto the bottom of the combustion pot where it forces its way upwardinto the burning zone, where it is consumed, the ashes overowing themouthof the-combuss tion pot.

The control consists of a thermostat diagrammatically shown at 20,`which is conveniently positioned in the dwelling at a point where thetemperature maintained will more or less control the temperaturethroughout the house, or, if desired, individual thermostats can be hadin the` separate rooms of the dwelling and the mechanism complicatedaccordingly to supply heat at the point de'- sired. VFor the purpose ofthe present'invention a single thermostat will suflice. The thermostatoperates in connection with the electrical cir cuit-which receives itspower from the lines vice to a predetermined point will cause acompletion of the circuit andjcontacting of the metal 22l with thecontact point 23, a battery 24 being interposed in .the circuit.

With the completion of the circuit by the con- 21 and 22. Acooling ofthe thermostatic deand27. .Thus the power from the lines 21 and 22 isconducted through the lines 28 and 29 through the motor 9 and line 30.In this manner the motor is started and the combustion mechanism put inoperation, the drive being transmitted to the screw conveyor and to theblower fan.

The operation as suggested is under maximum conditions, or the mechanismis completely stopped at which time the operation is substantially underbank fire conditions.

To supplement this control there is a fluid operated thermostat 31,positioned in the boiler, where it assumes the temperature of the water.The thermostat 31 is set at a predetermined temperature to actuate thediaphragm 32, and this in turn moves the contacting member 33 against oraway\,from

the contacting point 34.' Assuming that thek operation when operated vbythe thermostat .20. The operation of the thermostat 31, however, issupplementaryl to the thermostatic control 20 to prevent extinguishmentof the lirein the furnace when heat is not required in the dwelling.Furthermore, the operation due to the actuation of the thermostat 31will cause the mechanism to operate under optimum conditions. Thatis,the fuel will be supplied at the same rate and air 1n- ]'ected to thecombustion pot to consume the fuel under the most eicient conditions,rather than producing a slow burning fire which is a normal'practicewhere suicient combustion is -necessary only to keep the fire from`being extinguished.

It is understood air supply rates are carefully figured to proe duce theoptimum operating conditions when the control device actuates to startthe automatic stoker. There is no'regulation of drafts as in the commontype of furnace, making for operation under varying conditions, none ofwhich are perha s economically proper and efficient for the fiiel whichis being used. In the present showing the mechanism is described inconnection with a steam boiler,

but it will be understood that the secondary `for when the control 31may be positioned in the combustion space, as well as in the boiler, andthe minimum temperature governed accordingly.

By this invention, then, economical conditions of thermostat 20 in theheated there is a complete stoppa e of the fuel feed mechanism and theforce draft fan. This permits only the burning o f the residual fuel,which when consumed would allow the fire to be entirely extinguished, ifit were not for the auxiliary control within the combustion pot, whichfunctions when the furnace or' the water in the boiler is cooled to apredetermined ltemperature. This auxiliary control starting the'fuelfeed and force draft again institutes maximum operation until thetmperature in the boiler is restored to above 100, or at any otherpredetermined temperature selected as the minimum temperature.

I claim as my invention:

1. A heating system comprising. a boiler and combustion pot, anautomatic under feed Stoker for supplying fuel to said combustion pot, adual thermostatic control mechanism adapted to operate the stoker, onethermostatic mechanism functioning by variations in the temperature ofthe interior of the dwelling and `the other by predetermined minimumtemperature of the fluid temperature in the boiler, to preventextinguishment of the fire underl low heat requirement conditions.

2. A force draft furnace for hot water or 4 steam heating systems havinga power driven automatic under feed stoking element, adapted to beoperated under optimum combustion conditions, a anismA adapted tooperate the stoker, one thermostatic mechanism functioning by variationsin the temperature of the interior of the dwelling and the other bypredetermined Vminimum temperature of the boiler water to preventextinguishment of there.

WALTER M. oRoss.

that the fuel supply and combustion areat all times enforced,l

room reaches ,a predetermined temperaturel in the combustion pot or thewater dual thermostatic control mech-

